改变羊草长短、压片玉米添加比例对奶牛瘤胃瘤胃发酵情况的影响

发布时间：2018-07-06 13:40

本文选题：颗粒度 + 过瘤胃淀粉　；参考：《东北农业大学》2015年硕士论文

【摘要】：本论文包括以下内容:通过改变日粮中羊草的长短,监测干奶期奶牛瘤胃内发酵情况,从而得到在生产中,饲喂奶牛时最适宜的羊草长度。进而固定日粮中最适宜羊草长度的同时,通过改变日粮中压片玉米的替换比例来改变瘤胃降解淀粉的比例,从而对日粮中奶牛瘤胃降解参数以及奶牛瘤胃内p H值、VFA等指标的测定,确立适宜奶牛生产的淀粉添加比例。试验一:改变日粮羊草长短对奶牛瘤胃内发酵情况的影响改变日粮中羊草的物理长短,对奶牛瘤胃内p H值变化情况以及挥发性脂肪酸(volatile fatty acids,VFA)产量的影响及其机理进行探讨。选用4头处于干奶期装有永久性瘤胃瘘管的中国荷斯坦奶牛,采用4*4拉丁方的实验设计,研究四个水平羊草的颗粒度大小(2cm、4cm、8cm和18cm)分四组对奶牛进行饲喂。试验期为33d(天),其中前14d为预饲期,后12d为实验期。结果表明,在饲料营养价值不变的情况下,只改变粗饲料中羊草的物理长短,羊草长度在2cm时,其单位时间内瘤胃内p H值幅度变化大,TVFA产量显著高于4cm组、8cm组及18cm组(P0.01);羊草长度在18cm时,其单位时间内瘤胃内p H值幅度变化小与其他三组,瘤胃内p H值维持在6.40±0.80的较高水平。饲喂后2小时(9:00-11:00)四组间瘤胃液p H值差异极显著(P0.01),此时瘤胃液中乙酸含量2cm组显著高于4cm、8cm和18cm三组(P0.05),同时乙酸/丙酸比值2cm组显著高于4cm、8cm和18cm三组(P0.05)。由此可知,饲喂4种不同颗粒度羊草的日粮,不同时间点对瘤胃内pH值变化影响显著,瘤胃内乙酸、丁酸产量受颗粒度变化影响显著,其改变了瘤胃的发酵类型。干奶期奶牛日粮颗粒度过小或过大都会对奶牛产生一定不良影响。试验二:改变日粮中压片玉米的添加比例对奶牛瘤胃内酸度环境的影响在实验一的基础上,固定日粮中羊草长短,改变日粮中压片玉米添加比例,对奶牛瘤胃内VFA产量及p H值变化情况进行监测,选用试验一中的实验动物,采用4*4拉丁方的实验设计,研究饲粮中添加四个水平的压片玉米(0%,30%,60%,100%)对奶牛进行饲喂。试验期为33d(天),其中前14d为预饲期,后12d为实验期。结果表明,在S0组、S30组、S60组和S100组按0%、30%、60%和100%不同比例添加压片玉米后,日粮中淀粉瘤胃有效降解率(%)依次为62.97、71.85、80.74和89.63,随着日粮中瘤胃降解淀粉含量增高,瘤胃内p H值幅度变化大,四组间差异显著(P0.01);总挥发性脂肪酸产量(TVFA)、丙酸产量随压片玉米添加比例增高而显著增加(P0.01),而乙酸丙酸比呈显著降低(P0.01);单位时间内,瘤胃内氨态氮产量随日粮中压片玉米比例升高而显著上升(P0.01)。由此可得,饲喂添加不同比例压片玉米的日粮,改变日粮中瘤胃降解淀粉的比例,不同时间点对瘤胃内p H值及氨态氮变化影响显著,瘤胃内丙酸、TVFA产量受添加压片玉米比例变化影响显著,其改变了瘤胃的发酵类型。干奶期奶牛日粮中添加压片玉米对促进奶牛机体对日粮的吸收利用有积极的作用。综上所述,本实验得出以下结论:(1)改变日粮颗粒度大小,对干奶期奶牛瘤胃内酸度变化及瘤胃内发酵类型有显著影响,根据本研究中采食后12小时内奶牛瘤胃内酸度变化情况,羊草长度为8cm时,较适宜干奶期奶牛饲喂。(2)改变日粮中压片玉米的替换比例,对干奶期奶牛瘤胃酸度变化及瘤胃内发酵类型有显著影响,根据本研究中采食后12小时内奶牛瘤胃内酸度变化情况,建议干奶期奶牛饲喂替换30%压片玉米于日粮中最优。
[Abstract]:This paper includes the following contents: by changing the length of Leymus chinensis in the diet and monitoring the ruminal fermentation in the dry milk cows, the optimum length of Leymus chinensis in the production and feeding of cows is obtained, and then the most suitable length of Leymus chinensis is fixed in the diet, and the rumen degradation Lake is changed by changing the replacement ratio of the medium pressure slice corn. The ratio of powder was determined to determine the ruminal degradation parameters of dairy cows and the P H values and VFA in the rumen of dairy cows to determine the proportion of starch adding suitable for dairy production. Experiment 1: the change of the effect of the growth of the Rumen on the rumen fermentation in dairy cows changed the physical length of Leymus chinensis in the diet and the change of the P H value in the rumen of the cows. The effect of volatile fatty acids (VFA) and its mechanism were discussed. 4 Chinese Holstein cows with permanent rumen fistula in the dry milk period were selected to study the granularity of four Leymus chinensis (2cm, 4cm, 8cm and 18cm) in four groups of dairy cows. The test period was 33d (day), of which the pre 14d was the prefeeding period and the post 12D was the experimental period. The results showed that the physical length of Leymus chinensis was changed only when the feed value was unchanged. When the length of Leymus chinensis was 2cm, the P H value of the rumen in the unit time changed greatly. The yield of TVFA was significantly higher than that of the 4cm group, 8cm group and 18cm group (P0.01); the length of Leymus chinensis was 18 At cm, the P H value of Rumen in the rumen was small in the unit time and in the other three groups, and the value of P H in the rumen was maintained at a high level of 6.40 + 0.80. The P H value of the tumor gastric juice was very significant (P0.01) between the four groups of 2 hours (9:00-11:00) after feeding, and the 2cm group in the tumor gastric juice was significantly higher than 4cm, 8cm and three groups, and the ratio of acetic acid / propionic acid. The group was significantly higher than the 4cm, 8cm and 18cm three groups (P0.05). Therefore, the diet of 4 different granulation of Leymus chinensis was significantly affected by the changes of the ruminal pH value at different time points. The yield of acetic acid and butyric acid in the rumen was significantly influenced by the grain degree change, which changed the fermentation type of the rumen. A certain adverse effect was produced by the cattle. Experiment two: on the basis of the experiment one, the effect of changing the proportion of the addition of corn in the diet to the rumen acidity of the dairy cows was changed. On the basis of the experiment, the length of Leymus chinensis in the diet was fixed and the proportion of the corn in the diet was changed. The changes of the VFA yield and the P H value in the rumen of the cows were monitored. The experimental design of 4*4 Latin square was used to study the feeding of four levels of pressed corn (0%, 30%, 60%, 100%) in the diet. The test period was 33d (day). The pre 14d was the pre feeding period and the post 12D was the experimental period. The results showed that the diet was added to the S0, S30, S60 and S100 groups after the addition of 0%, 30%, 60% and 100% to the corn. The effective degradation rate (%) of starch rumen was 62.97,71.85,80.74 and 89.63 in the grain. With the increase of ruminal degradation starch content in the diet, the P H value in the rumen changed greatly, the difference between the four groups was significant (P0.01), the total volatile fatty acid production (TVFA), the propionic acid yield increased significantly with the increase of the proportion of the pressed corn (P0.01), and the ratio of propionic acid to propionic acid. There was a significant decrease (P0.01); in the unit time, the yield of ammonia nitrogen in the rumen increased significantly (P0.01) in the diet (P0.01). Therefore, the ration of the rumen degraded starch in the diet was changed, and the effects of the Rumen on the P H value and the ammonia nitrogen in the rumen were significantly affected. The yield of propionic acid, TVFA yield was significantly affected by the change of the proportion of adding pressed corn, which changed the type of rumen fermentation. The addition of pressed corn to the diet of dairy cows in the dry milk period had a positive effect on promoting the absorption and utilization of dairy cows. In summary, the following conclusions were drawn as follows: (1) to change the grain size of the diet and to the rumen of dairy cows in the dry milk period. The change of internal acidity and the type of rumen fermentation have significant influence. According to the change of the rumen acidity in the rumen of dairy cows within 12 hours after feeding in this study, when the length of Leymus chinensis is 8cm, it is better to feed the cows in the dry period. (2) change the replacement ratio of the pressed corn in the diet. There is a significant shadow on the rumen acidity and the type of rumen fermentation in the dry milk cows. According to the change of acidity in the rumen of dairy cows within 12 hours after feeding, it is suggested that the replacement of 30% slices of corn in dry milk period is the best in the diet.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823.5

【参考文献】